Hall v. Conocophillips
248 F. Supp. 3d 1177
W.D. Okla.2017Background
- Samantha Hall sued Conoco Inc., ConocoPhillips and Phillips 66 alleging benzene emissions from a Ponca City refinery caused her AML with inv(16). Plaintiff retained experts: Dr. David Mitchell (air dispersion/modeling), Dr. Steven Gore (hematologist/causation and dose), and Dr. Mary Calvey (environmental epidemiology).
- Defendants moved to exclude expert testimony under Daubert/Rule 702; hearings addressed Mitchell, Gore, and Calvey. Supplemental declarations by Mitchell and Gore relying on a newly consulted scientist (Dr. Ede) were challenged as untimely under Rule 26.
- Dr. Mitchell used AERMOD to model stack and fugitive benzene emissions (1988–1992 period emphasized); he reported very high short-term (one-hour) fugitive concentrations and provided modeled outputs to toxicologists. He later changed inputs (increasing emissions) after receiving Dr. Ede’s information.
- Dr. Gore relied on Mitchell’s modeled concentrations (using the peak one-hour concentration) to compute a cumulative benzene "dose" and opined benzene substantially contributed to Hall’s AML. Gore admitted he deferred key exposure-metric selection to Mitchell and made calculation errors (duration, units, terminology).
- Dr. Calvey offered epidemiologic opinions that benzene causes AML generally and AML inv(16) specifically and that Hall’s in utero/early-childhood exposures were likely causative; she had not researched literature specific to AML with inv(16) and did not quantify or reliably establish Hall’s exposure or adequately rule out alternative causes.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Timeliness of Mitchell/Gore supplemental declarations (Rule 26) | Supplements updated models based on new info from Dr. Ede and responded to challenges; were justified. | Declarations contain new expert-driven opinions submitted after deadlines, prejudicing defendants and reopening discovery. | Court struck/disregarded portions of Mitchell and Gore opinions based on Dr. Ede’s information as unjustified and prejudicial. |
| Reliability of Mitchell’s air modeling (methodology/implementation) | Mitchell used appropriate dispersion model (AERMOD) and later relied on EPA materials; provided modeled concentrations for toxicologists. | Mitchell improperly merged many stack and fugitive sources into single points, used unsupported point-source assumptions, failed to follow guidance or validate against sampling, and reported maxima inside refinery. | Court identified significant methodological problems but declined to fully resolve Mitchell’s admissibility because exclusion of other experts made resolution unnecessary. Portions tied to Dr. Ede were excluded. |
| Gore’s dose calculation and specific causation (expertise & methodology) | Gore relied on modeling data provided by Mitchell and performed standard dose calculation to reach causation opinion. | Gore lacked experience calculating exposure/dose, deferred critical metric choice (peak hour) to Mitchell, made calculation errors and used inappropriate exposure assumptions. | Gore’s dose opinion excluded as unreliable; his differential-diagnosis specific-causation opinion excluded because plaintiff lacked admissible exposure proof and Gore’s analysis failed to reliably rule in/rule out alternatives. |
| Calvey’s general and specific causation (epidemiology and differential diagnosis) | Calvey used a weight-of-evidence, qualitative approach and considered exposure history to rule in benzene and rule out other causes. | Calvey failed to review peer-reviewed literature specific to AML inv(16), did not quantify or substantiate plaintiff’s exposure, and inadequately considered alternative (including idiopathic) causes. | Calvey’s opinions on general causation for AML inv(16) and her specific-causation differential diagnosis were excluded as unreliable under Daubert. |
Key Cases Cited
- Daubert v. Merrell Dow Pharm., 509 U.S. 579 (court’s gatekeeping obligation to ensure expert reliability)
- Kumho Tire Co. v. Carmichael, 526 U.S. 137 (Daubert gatekeeping applies to all expert testimony)
- Bitler v. A.O. Smith Corp., 400 F.3d 1227 (10th Cir.) (standards for differential diagnosis and expert reliability)
- United States v. Nacchio, 555 F.3d 1234 (10th Cir.) (qualification inquiry for experts)
- Jacobsen v. Deseret Book Co., 287 F.3d 936 (10th Cir.) (Rule 26 violation—supplementation factors: prejudice, cure, disruption, bad faith)
- Hollander v. Sandoz Pharm. Corp., 289 F.3d 1193 (10th Cir.) (definition and limits of differential diagnosis in causation opinions)
- Norris v. Baxter Healthcare Corp., 397 F.3d 878 (10th Cir.) (distinction between general and specific causation requirements)